Search

Positron emission tomography has, for 30 years, been used in numerous case-control studies searching for hypothesized differences in the density of neuroreceptor or transporter proteins in psychiatric disorders such as schizophrenia and depression. In most cases, the results have not been conclusive. One reason could be the sizeable interindividual variability in biochemical markers, which in twin studies have shown to emanate from both environmental and genetic factors, leading to low statistical power for the detection of group effects. On the other hand, the same interindividual variability has served as an opportunity for correlative studies on the biological underpinning of behaviour. Using this approach, a series of studies has linked markers for the dopamine and serotonin system to personality traits associated with psychiatric conditions. Based on increasing evidence for the view that many psychopathological states represent extremes of a continuum rather than distinct categories, this research strategy may lead to new biological insights about the vulnerability to and pathophysiology of major psychiatric disorders.This article is part of the theme issue 'Diverse perspectives on diversity: multi-disciplinary approaches to taxonomies of individual differences'., (© 2018 The Author(s).)

Aim: Basic studies indicate magnesium deficiency as one of the important, but often neglected, risk factors aggravating the course of borderline disorders (BD). A clinical verification of this notion has been conducted., Material and Methods: Authors studied 62 patients with BD, aged 25-65 years, of inpatient and outpatient settings. Contents of magnesium and other blood electrolytes were determined., Results: Authors found an extremely high prevalence of very low levels of magnesium (Mg) in erythrocytes (<0.3 mmol/l) in patients with BD compared to controls (patients without BD, Mg (er.) 1.62±0.48 mmol/l). It has been shown that low Mg levels in the plasma and red blood cells are associated with a significantly increased risk of the following diagnoses: F07 «Personality and behavioral disorder due to brain disease, damage and dysfunction» (p<0.0016), F21 «Schizotypal disorder» (p<0.0005) and F34 «Persistent mood [affective] disorders» (p<0.0001). The use of Magne B6 Forte (4 tablets/day, 30 days, then 2 tablets/day for 1 year) resulted in a significant increase in the Mg levels in the plasma and erythrocytes, the compensation of anxiety and depressive symptoms, improvement of sleep and general health of the patients, reduced consumption of antidepressants (by 30%)., Conclusion: Administration of the drugs based on organic salts of magnesium per os improves the condition of patients and reduces their need in pharmacotherapy.

Objective: To analyze the capability of a set of neurobiological and psychopathological variables to discriminate bulimia nervosa (BN) patients from healthy controls., Method: Seventy-five female patients with purging BN and 30 healthy controls were compared for psychopathology (impulsivity, borderline personality traits, depressive symptoms and self-defeating personality traits) and neurobiological parameters reflecting hypothalamic-pituitary-adrenal axis activity (morning serum cortisol before and after dexamethasone) and monoamine activity (24-hour urinary excretion of norepinephrine, serotonin, dopamine, and their main metabolites: 3-methoxy-4-hydroxyphenylglycol, 5-hydroxyindoleacetic acid, and homovanillic acid). Furthermore, the relationships between the 2 sets of variables were compared in the 2 samples., Results: BN patients displayed higher impulsivity, more severe depressive features, and more borderline and self-defeating personality traits than controls. The 4 psychopathological variables were strongly interrelated in patients, whereas only depressive features correlated with self-defeating personality traits in controls. Patients had lower 24-hour excretion of serotonin and dopamine than controls, as well as lower ability to suppress cortisol. The relations between the biochemical and the psychopathological variables were only significant in the BN patients, but not in the control group. When discriminant analysis methods were applied, patients and controls differed for psychopathology (impulsive behaviors and borderline personality traits) and biological parameters (baseline cortisol and dopamine excretion), but when the variables were analyzed together, the differences in neurobiological parameters appeared as mediated by the psychopathological status., Discussion: Our results suggest that hypothalamic-pituitary-adrenal axis activity, dopamine activity and other biological parameters are worthy of further study as potential dimensional markers of BN, although they seem to depend on the psychopathological status of the patients, in such a way that the psychopathological items associated with emotional instability (impulsivity and borderline personality traits) seem to be more reliable as clinical markers at the time being., (Copyright © 2011 S. Karger AG, Basel.)

The high prevalence of anger, impulsivity and violence in cocaine addiction implicates chronic cocaine use in the compromise of higher-order inhibitory control neurocognitive processes. We used the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) anger content scale as a personality measure of inhibitory control and examined its association with glucose metabolism in the lateral orbitofrontal gyrus (LOFG) at rest as measured by positron emission tomography with 2-deoxy-2[(18)F]fluoro-D-glucose (PET (18)FDG) in 17 recently abstinent cocaine-dependent subjects and 16 comparison subjects. Three additional variables--the MMPI-2 depression content scale, metabolism in the medial orbitofrontal gyrus (MOFG) and the anterior cingulate (AC) gyrus--were inspected. When level of education was statistically controlled for, the LOFG was significantly associated with anger within the cocaine group. No other region was associated with anger within the cocaine-dependent group, and the LOFG did not correlate with depression within any of the study groups. The present study confirms earlier reports in demonstrating a positive association between relative metabolism at rest in the LOFG and cognitive-behavioral and personality measures of inhibitory control in drug addiction: the higher the metabolism, the better the inhibitory control.

The central issue raised in this paper is: can stress cause depression? Phrased more precisely: can stress cause brain disturbances thought to underlie (certain forms of) depression or particular components of the depressive syndrome. Focussing on 5-hydroxytryptamine (5-HT) and the stress hormones, this question was answered in the affirmative, based on the following two considerations: changes in the 5-HT and stress hormone systems produced by sustained stress mimic to a substantial extent the disturbances in these systems that may be observed in depression. Substantial evidence indicates that the 5-HT and stress hormone disturbances in depression are of pathophysiological significance and not merely a consequence of the depressed state or a product of stress generated by the depressed state. Furthermore, the question was raised whether a depression type could be identified particularly stress-inducible. This question, too, was answered in the affirmative. The depression type in question was named anxiety/aggression-driven depression and characterized on three levels: psychopathologically, biologically and psychologically. Preferential treatment of this depression type was discussed. In studying stress-inducible depression, biological depression research should shift focus from depression per se to the neurobiological sequelae of stress. Treatment of stress-inducible depressions and particularly its prevention should be geared towards reduction of stress and stress sensitiveness, utilising both biological and psychological means.